Condensation products of the modified urea-aldehyde type



- invention is concerned more particularlyatented Nov. 29, 1945 CONDENSATION raonuc'rs OF THE MODI- D UREA-ALDEHYDE TYPE Gaetano F. DAlelle, Pittsfield, Masa, assignor to General Electric Company, a corporation of New York No Drawing. Application February 17, 1939, Serial No. 256,998

16 Claims.

This invention relates to new and useful compositions of matter comprising new reaction prodnets and to the production of the same. The with condensation products obtained by reaction of an amide, an aldehyde and an aldehyde-reactable organic amphoteric substance free from polypeptide linkages. Specifically the invention relates to new and useful compositions of matter comprising a resinous product of reaction, in the absence of a protein, of ingredients comprising (1) a polyamide selected from the class consisting of urea, thiourea, phenyl thiourea, malonic diamide, succinic diamide, citric triamide and phthalamide, (2) an aldehyde and (3) a crystalloidal aminocompound selected from the class consisting of amino carboxylic acids and salts of the said amino acids. Thus the amino compound employed in practicing the claimed invention may be, for example, a proteinaceous ingredient or protein derivative consisting essentially or substantially of a crystalloidal amino carboxylic acid. i

The organic amphoteric substances and their derivatives used in practicing this invention are not to be confused with the proteids and partially hydrolyzed proteids, examples of which are glycinin, zein, casein, legumin, gliadin and ph-aseolin, merely to mention a few. These proteid compounds are non-crystalloid, water-insoluble bodies having polypeptide linkages and the colloidal properties of the high molecular weight proteins, as exemplified by viscosity and osmotic pressure phenomena. When the proteids or their alkali salts are plasticized, for example with water, alcohol, etc.,'or when they are reacted with active methylene-containing bodies, in either case plastic compositions are obtained. In contrast with the proteids the amphoteric substances and their derivatives employed in carrying this invention into effect are crystalloids, or, if impure, may be obtained in crystalline form by simple recrystallization processes. They exhibit the properties typical of crystalloids, for example, sharp melting or decomposition temperaturesl In solution, the values of their freezing point depressions, boiling point elevations. and osmotic prestsdures can be approximated by simple calculaons.

The free amino acids represent the simplest aldehyde-reactable organic amphoteric substances having no polypeptide linkages that are known. Theoretically the simplest possible amino acid would be carbamic acid or amino formic acid, NHQCOOH, which, however, is not known to exist in the free state. Derivatives of carbamic acid, such as ammonium carbamate, NH2COO'NH4, and ethyl carbamate, NHzCOOCzHe, are known and are quite stable. Of the amino acids, glycine or amino acetic acid, NHzCHzCOOH, is the simplest known to exist in the free state.

It will be noted that such organic amphoteric substances as amino acids, of which glycine is one of numerous examples, contain both an acid group, COOH, and a basic group, N'H2. The amphoteric substances on ionization give simultaneously two ions, one negatively charged and the other positively charged, leaving a residual molecule with two equal and opposite charges. Ionically, the equilibrium may be represented thus:

normrcmcoon It is known that free or uncombined amino acids (hereinafter for brevity referred to merely as amino acids), for example amino carboxylic acids and amino sulfuric acid. (amino sulfonic acids), can react with basic substances such as sodium and potassium carbonates and hydroxides, ammonia, trimethyl amine, pyridine, morpholine, aniline, cyclohexylamine, naphthylamine, diethanolamine and the like to give the corresponding salts of the amino acid. These salts are basic not because of the added alkali, but because the NH2 group of the amino acid has been freed of the neutralizing efiect of the COOH group, this group being neutralized by the added base. Thus, sodium glycinate, NHzCHzCOONa, is alkaline in its reactions. Similarly, the original -NH2 group of the amino acid can be neutralized by added acid, such as sulfuric, hydrochloric, acetic, benzoic and the like, resulting in acidic glycine salts. In these salts the COOH group is free to ionize as an acid, since the influence of the -NH2 group has been removed by the added acid. Thus, glycine hydrochloride,

HCLNHzCHiCOOH is acidic in nature.

It is also known that the amino acids can be reacted (condensed) with aldehydes to give methylol derivatives. For example, when formaldehyde and glycine are condensed, acidic lnethylol glycine, HOCHzNHCI-IzCOOH, is obtained. However, if more than one hydrogen of the amino group is replaced by R (alkyl, aryl or aralkyl group), the resulting substituted amino acid will not react with an aldehyde. Thus, taking a substituted glycine wherein one of the amino hydrogens of the original glycine, NH2CH2COOH, is replaced by R to produce RNHCI-IaCOOH, such substituted glycine is capable of reacting with an aldehyde. On the other hand, when both hydrogens of the nitrogen group are replaced by R, the resulting substituted glycine, RzNCHzCOOI-I, is incapable of reacting with aldehydes to form methylol derivatives. By an aldehyde-reactable organic amphoteric substance, specifically an aldehyde-reactable amino acid, as used herein, is accordingly meant a substance capable of reacting with an aldehyde to form a methylol derivative, more particular y with reference to an amino acid one wherein at least one hydrogen of the amino group is available for replacement by a methylol grouping.

The amino acids usually are classed accordin to their chemical nature.

Class I includes the aliphatic, mono-amino mono-carboxylic acids such as glycine or glycocoll, alanine, a-amino butyric acid, a-amino valeric acid, valine or u-isopropyl a amino acetic acid, glycoleucine, leucine or aisobutyl a-amino acetic acid, isoleucine or e-aminop-methylethyl propionic acid, serine or p-hydroxy a-amino propionic acid, cysteine or ,B-thio u-amino propionic acid.

Class II includes the mono-amino dicarboxylic acids such as aspartic acid and glutamic acid.

Class III embraces the isocyclic amino acids such as tyrosine and phenyl alanine.

Class IV includes the heterocyclic amino acids such as tryptophane or u-amino p-indole propionic acid, proline which is a-pyrrolidine carboxylic acid, histidine or a-amino c-imidazole propionic acid and oxy-proline.

Class V includes the diamino mono-carboxylic acids such as arginine or a-amino a-guanidine valgric acid and lysine or a, e-diamino caproic acl Class VI includes the heterogeneous amino acids, examples of which are the ortho, meta and para amino benzoic acids, beta amino propionic acid, sulfamic acid (NHzSOaOI-I), and beta amino ethyl sulfonic acid (Nnzcrncrnsoioml I have discovered that the reaction product of an aldehyde-reactable organic amphoteric substance which does not have polypeptide linkages (examples of which have been given above), or one of its derivatives, e. g., a salt thereof, and an aldehyde (e. g., formaldehyde, acetaldehyde. propionaldehyde, butyraldehyde, acrolein, methacrolein, benzaldehyde, etc., or compounds en- ,gendering aldehydes such as paratormaldehyde and paraldehyde) can be reacted with amides, more particularly urea, thiourea and other polyamides such as above mentioned, to give new and useful compositions of matter, characteristic properties of which are hereinafter given. If we designate any of the amphoteric substances or their derivatives in the six classes above described as R-CH-O 0M an aldehyde as R'CHO, and an amide as the general equation for the reaction may be written as follows:

NH: aldehyde amino acid R mcthyiol amino acid amide It and R in the above formulas may be hydrogen may be replaced by its equivalent, such as sulfur in the thioamides,

where X is an element or radical bonded to the carbon atom by a double bond. The reaction does not exclude polyamides, since the number of the amide groups does not aifect the nature of the reaction. Carbamide (urea), thiocarbamide (thiourea), phenyl thiocarbamide (phenyl thicurea) and amides of polybasic acids, for example, malonic diamide, succinic diamide, citric triamide, phthalamide and the like, may be used.

Since the reaction between an aldehyde ,and the amphoteric substance used in practicing this .invention depends on the NH: group of the .amphoteric substance, the remainder of the amphoteric molecule may be modified in the form of a derivative such as the lithium, barium, calcium, sodium or potassium salts, the ammonium salt, the organic ammonium salts, the esters, the amides or, in general, the modifications that can be introduced to an organic radical such as COOH.' or the inorganic radical -SO2OH. Thus, I have found that I can condense sodium glycinate and formaldehyde to give methyloi sodium glycinate, and that the latter can be condensed with an amide such as acet amide to give the sodium salt of N-(methylene glycine) acetamide,

o o o CHsC ONHCHSNHCHlC 0 ONE Upon acidification of this sodium salt with an inorganic acid N- (methylene glycine) acetamide.

cmconncmmrcmooon is obtained. The starred positions in the above salts which function as buffers. One embodiment of my invention is based on my discovery that definite conditions of pH can be readily and 5 easily obtained by using a definite, predetermined formulas and in formulas hereinafter given desigadjusted ratio of the herein-defined amphoteric nate potentially reactive positions. substance to one of its derivatives, for example It is not necessary to isolate the methylol dea sodium or potassium salt thereof, as hereafter rivatives of the amphotericsubstance before conmore fully described. This control of pH differs densation with the amide. The aldehyde and the i0 fundamentally from the standard or convenamphoteric substance, specifically an aldehydetional processes in that the control comes from reactable amino acid, may be mixed in a. suitable an internal mechanism whereby the molecules solution, as for example an aqueous solution, and of the reactants, as well as the molecules resulting allowed to react, followed by the addition of an from the reaction, act to control the pH conditions. amide. The reaction is allowed to proceed either In carrying my invention into efiect the ratio at room temperature or at any suitable elevated of the reactants to each other has material intemperature up to and including the boiling point fiuence upon the composition and characteristics of the solution at atmospheric or superatmosof the final product. In the case of monoamides" pheric pressures. Advantageously the reaction the ratio of reactants is-naturally limited, beis carriedout under refluxing (boiling) condicause the amphoteric substance and the amide tions, the reaction vessel being provided with a have only one reactive position. With polysuitable reflux column for this purpose. anrides, however, the ratio of reactants can be I have also found that the desired end-prodvaried over a widerange, due to the plurality of ucts can be obtained in a one-step process by reactive positions in the amide molecule. The initially mixing all the reactants together, speeffect of mol ratios of reactants upon the nature cifically an amide, aldehyde and an aldehydeof the final products will be understood more reactable organic amphoteric substance free from readily by reference to the table, wherein glycine polypeptide linkages (with or without one of its is mentioned as illustrative of the amphoteric derivatives) and simultaneously reacting these substance, urea as illustrative of the polyamides, components. In this case the reaction which and formaldehyde as illustrative of an aldehyde.

Moi ratio of reactants Reaction product comprising mainly- Glyoine Urea gga a a a o o A 1 a 2n (-CHg-If-CON'HCH: nncnicoon 8 0 Q Q a I! B 1 n 'n moonncm-(Nnconncmn-lNncnicoon 0 0 0 0 o 1 1 1 NHaCONHCHaNHCHaCOOH a a a a o n 1 1 2 nocmNncoNncmNnomcoon 0 t i n 2 1 2 Hooc -cH,NHcH,NH),co

Norm-In the foregoing table 11 has a numerical value of l or more.

takes place may be written thus:

' hyde amino acid I 11,0 -CON(|JHNH-CH-CO0M R! R, R and M appearing in the above formulas have the same meanings as previously explained with reference to a two-step reaction between the components.

The condensation of the methylol amino acid When the mol ratios of reactants are relatively low, for example as shown under C, D and E in the table, crystalline bodies are obtained. With an increase in mol ratios of the formaldehyde, or urea and formaldehyde, with respect to the amphoteric substance, the products gradually approach a colloidal state.

The products shown by way of illustration in the table may be described as primary products. They are potentially reactive compounds, the starred positions indicating the favorable points of reaction. They may react with themselves to produce larger molecules or they may be modified in various ways, as by reacting them with other potentially reactive compounds. The

group, for example, may be converted to a salt, an ester, an amide, or the like. Also, some of the or the These substances are usually acids, alkalies or groups may be reacted with more aldehyde. whereby in certain cases secondary resinous products may be obtained from crystalline primary products, which secondary products may be used as adhesives or as surface coating materials. They also have other applications, for example in casting, laminating and molding uses, with or without fillers, plasticizers, dyes, pigments or other modifying agents. The I group may be reacted with alcohols to give ether compounds having the grouping ROCHaNH-, where R is the residue of a monohydric or polyhydric alcohol. In the utilization of any primary condensation products for the preparation of secondary products, I need not isolate such products before further reaction.

In the preparation of primary or secondary products, the reaction may be carried out, if desired, in the absence of a solvent, or in an aqueous solvent, or in a non-aqueous solvent such as dioxane, methyl alcohol, butyl alcohol, glycol monoacetate, ethylene glycol, glycerine, diethylene glycol, ethylene glycol mono-alkyl ethers, and the like.

In the production of resinous materials, it is not necessary to use a pure or homogeneous amphoteric substance or one of its derivatives. Thus, I may use a crude orpartially purified mixture of amino acids.

The products of condensation of an aldehyde, an amide and the herein-defined amphoteric substance may be recovered simply by evaporation of the solvent or by precipitation methods, followed by centrifuging or filtration.

In making the ordinary urea-aldehyde resinous I condensation products, the condensation catalysts, the buffers used in pH control and the latent acidic curing catalysts are bodies foreign to the reaction. In practicing this invention, wherein an amide, an aldehyde and an aldehydereacta-ble organic amphoteric substance free from polypeptide linkages, or its derivative, are condensed, the amphoteric substance (1) can behave as the catalyst for the condensation, and at the same time actually participate in the reaction; and (2) both as a reactant and as a product of reaction the amphoteric substance alone or in the presence of its derivative, can control the pH of the mass, not by a foreign mechanism, but by becoming an integral part of the condensation product. Further, by using a predetermined adjusted ratio of amphoteric substance to that of, say, an alkaline derivative thereof, a heathardenable resinous condensation product of any desired internal acid condition and of controllable curing rate can be obtained.

Taking glycine and sodium glycinate as illustrative of an amphoteric substance and of an alkaline derivative thereof, the following diagram shows the step-by-step changes which take place when each reacts first with an aldehyde, s ecifically formaldehyde, and then with an amide, specifically urea. (It will be noted that the second reaction shown in the right-hand column is a reaction, in the absence of a protein, between ingredients including an N-methylolglycine salt, specifically the sodium salt of N- methylol glycine, and urea.)

. NHQOONHOilNHOHSOOOH NHzCONH 11B ql elm sodium alycinate NmCBECOOH NHsCHnCOONB neutral alkaline LCHIO lCHxO HOGHr-NH H1000]! HOCHINH H ONa acidic neutral NHaC ONH: LNHzC ONH:

acidic at a] As previously pointed out, glycine, which is neutral, or sodium glycinate, which is alkaline, reacts with formaldehyde to give acidic methylol glycine, HOCHaNHCHzCOOH, and neutral methylol sodium glycinate, HOCHsNI-ICI-hCOONa, respectively. However, sodium glycinate is much more reactive than glycine. Hence, by taking a solution formed of, for example, 1 mol urea, 1 mol formaldehyde, mol glycine and mol sodium glycinate, th alkaline glycinate condenses with the formaldehyde and the ureamore rapidly than the glycine, producing a neutral molecule. At the same time the glycine also condenses with the urea and formaldehyde to produce acidic molecules. In this way there is obtained a solution with a definite pH value for a particular mixture of condensation products, specifically a mixture consisting of V mol a! methylene glycine urea,

NHsCONHCHzNI-ICHzCOOH and mol of the sodium salt of methylene glycine urea, .N'I-hCONHCHaNI-ICI-IzCOONa. On the other hand, if the original glycine-glycinate ratio were mol to mol, the final solution would be much more acidic than in the example above mentioned by: reason of the fact that it would consist of mol of methylene glycine urea and A; mol of the sodium salt f methylene glycine urea.

From the foregoing it is evident that a mixture of glycine and glycinate in the described condensation reaction shifts the pH medium from the high or alkaline side toward the low or acid side, the desired range of pH being determined by the ratio of reactants and therefore definitely controllable. It will be understood, of course, that this is true not only of glycine and sodium ycinate, but also of other aldehyde-reactable organic amphoteric substances free from polypeptide linkages, and derivatives thereof, numerous examples ofwhich previously have been thereof, for instance sodium glycinate, to be condensed with an aldehyde and an amide, I need not prepare the glycine and the glycinateseparately, but may form a salt of glycine by adding, for instance, a suitable alkali, as for example sodium hydroxide, to glycine itself in such an amount that the desired glycine-glycinate ratio will be obtained.

In order that those skilled in the art better may understand how the present invention may be carried into effect; the following specific examples are given to illustrate the invention. All parts are by weight, and the formalin is a tech nical grade of aqueous formaldehyde containing approximately 37.1% formaldehyde.

NHaCONHCI-IaNHCHzCOOI-I.

Example 2 Mols Urea 1 Formaldehyde 1 Sodium glycinate (from reaction of NaOH and glycine) 1 Four parts NaOH were dissolved in a minimum of water and added to 7.5 parts glycine in 5 parts water to prepare sodium glyclnate. 8.05 parts formalin were next added, resulting in the liberation of heat. 6 parts urea in 8 parts water were added and the whole heated to 70 C. for V2 hour. The condensation product thereby obtained was insoluble in alcohol. The aqueous solution of the condensation product was twice extracted with an equal volume 01 alcohol to remove alcoholsoluble material. The aqueous solution was evaporated, leaving a white sticky mass which dried to a hard powder. It comprised the sodium salt of N-(methylene glycine) urea,

nmconncnmncrncoona 0n acidification a product corresponding to that of Example 1 was obtained.

Example 3 Mols Urea 1 Formaldehyde 2 Glycine 2 Three parts urea in 4 parts water were added to a solution of 8.05 parts formalin and 7.5 parts glycine. Considerable heat was liberated. In about 2 hours a thick, hard cake of crystals was obtained. A solution formed of equal parts alcohol and water was added to make a slurry.

This was followed by filtration. After drying at 70 C., 12.26 parts of a white crystalline ,condensation product were obtained. This product. which melted with decomposition at about 173 C., comprised N,N, di-(methylene glycine) urea, CO(NHCH2NHCH2COOH)2.

Example 4 Mols Urea l Formaldehyde 2 Sodium glycinate (from reaction of NaOH and glycine) 2 urea, C0 (NHCH2NHCH2COONE) 2. On acidiflcation with hydrochloric or sulfuric acid a product corresponding to that of Example 3 was obtained.

Example 5 Mols Thiourea 1 Formaldehyde '1 Glycine 1 tion was evaporated at 70 C. to almost dryness,-

leaving a damp, white, hard cake of crystalline material. The crude crystals were filtered dry by suction and dried at 70 C. 2 parts of a condensation product which melted with decomposition at about 177 C. were obtained. The crude product comprised N-(methylene glycine) thiourea, NHaCSNHCHzNHCHaCOOH.

Example 6 p Mols Thiourea 1 Formaldehyde 2 Glycine 2 One and fifty-two hundredths (1.52) parts thiourea, 3.24 parts formalin and 3 parts glycine in 2 parts water were mixed, and on heating for 1 hour at 70 C. resulted in a clear, homogeneous solution. On evaporation, 4.9 parts of a light cream-colored powder having an indistinct melting point were obtained. Foaming and decomposition began at about 144; C. The product, which melted completely at about 158 C. to a thick, viscous, reddish liquid, comprised N,N, di- (methylene glycine) thiourea.

- Example 7 Mols Thiourea 1 Formaldehyde 2 Glycine 1 One and fifty-two hundredths (1.52 parts thiourea, 3.24 parts formalin and 1.5 parts glycine in 2 parts water were mixed and heated at 70 C.

for 1 hour, resulting in a cloudy, homogeneous solution which, upon evaporation, yielded a light, cream-colored crystalline powder with an indefinite melting point. Gradual swelling started at about C.-and melting was completed at about C. The product comprised N-methylol, N-(methylene glycine) thiourea.

Example 8 Mols Thiourea 1 Formaldehyde 2 Glycine 1 Butyl alcohol 1 One and fifty-two hundredths (1.52) parts thio- Erample 9 Mole Malonic diamide 1 Formaldehyde 1 Glycine 1 Two and four hundredths (2.04) parts malonic diamide, 1.62 parts formalin and 1.5 parts glycine in 2 parts waterwere mixed and heated at 70 C. for V hour, resulting in a clear homogeneous solution. On evaporation to dryness at 70 C. there resulted 3.44 parts of resinous, yellowish powder-with an indefinite melting point. At 180 C. on a hot plate the condensation product cured to a soft film. The addition of paraiorm at 180 C. increased the hardness of the film.

Example 10 Mols Malonic diamide 1 Formaldehyde 2 Glycine 1 Two and four hundredths (2.04) parts malonic diamide, 3.24 parts formalin and 1.5 parts glycine in 2 parts water were mixed and let stand for 24 to 48 hours, then heated for 1 hour at 70 C. There resulted a clear, homogeneous solution. This solution was evaporated, yielding a yellowish gummy resin that advanced to a fairly soft gummy film upon heating at 180 on a hot plate. The addition of parai'orm seemed to accelerate this conversion at 180 C.

Example 11 Mols Phenyl thiourea 1 Formaldehyde 2 Glycine 1 One and fifty-two hundredths (1.52) parts phenyl thiourea, CeHsN'HCSNl-h, 1.62 parts formalin and 0.75 part glycine with 5 parts water were refluxed for about 1 hour. A condensation product with resinous characteristics formed as a cake in the reaction flask on cooling. The supernatant liquid was decanted and a small amount of waxy material also was isolated from the solution by evaporation. The crude condensation product was dried at 70 C., and the dried product melted at 92-100 C.

Example 12 J Mols Urea 1.25 Methacrolein 1.0 Glycine 1.25

. Example 13 Mols 'Urea 1 Formaldehyde 2 GLvcine 1 ylene e s solution with the evolution of heat.

when 1.2 parts urea, 3.24 parts formalin, 1.5 parts glycine and 1.24 parts ethylene glycol were mixed, the solution became slightly warm. Alter cooling to room temperature the mixture was refluxed for two hours, resulting in a clear homogeneous solution, which, upon evaporation at 70 0., yielded a light, pale yellow resin. Upon heating at 180 C. on a hot plate it was first converted to a viscous resinous mass which, on longer heating, became inlusible.

Example 14 Mols Urea 1 Formaldehyde 2 Sodium glycinate (from reaction of NaOH and glycine) 1 To a solution of 1.5 parts glycine and 0.8 part NaOH in 2 parts water there were added 1.2 parts urea and 324 parts formalin. The mixture was allowed to stand in a stoppered flask for 1 hour at 70 C., then evaporated, leaving 3.84 parts of a clear homogeneous resinous-appearing mass, which was converted to a dry white powder upon heating at 180 C. on a hot plate.

Example 15 Mols Urea 1 Formaldehyde 2 Sodium glycinate (from reaction of NaOH and glycine) 1 Isopropyl alcohol 1 To a solutionof 1.5 parts glycine and 0.8 part NaOH in 2 parts water were added 1.2 parts urea, 3.24 parts formalin and 1.2 parts isopropyl alcohol. The mixture was refluxed for 1 hour. The solution was then evaporated at 70 0., leaving 3.71 parts of a light-colored condensation product with resinous characteristics. The resin advanced at 180 C. to a hard powder.

Example 16 Mols Urea 1 Formaldehyde 3 Glycine 1 When 1.2 parts urea, 4.86 parts formalin, 1.5 parts glycine and 2 parts water were mixed, a clear solution resulted with the liberation of heat and with a gradual increase in viscosity. 0n evaporation of the solution at 70 C., 3.2 parts of a light greenish, hard, resinous condensation product were obtained. It did not melt definitely, but showed swelling at 124 C. At 180 C., the product was plastic.

Example 17 Mols Urea 1- Formaldehyde 4 Glycine 1 One and two-tenths (1.2) parts urea, 6.48 parts formalin, 1.5 parts glycine and 2 parts water were mixed, resulting in a clear homogeneous The condensation product was concentrated by evaporation at 70 C., leaving 3.65 parts of a pale yellow, hard resin with an indefinite melting point. At 180 C. on a hot plate the condensatiofi'product produced a viscous melt which hard- I 1 ened rapidly under the applied heat.

Example 18 idols. Malonic dia i Formaldehyde 3 Glycine v Vs Sodium glycinate (from reaction oi sodium hydroxideand glycine) it Two-tenths (0.2) part NH in 2 parts water were mixed with 0.75-part glycine (corresponding to a solution of 0485 part sodium glycinate and 0.375 part glycine). This mixturewas added to 2.43 parts formalin and 1.02 parts malonic diamideand let stand at room temperature for about 15 hours. resulting in a clear homogeneous solution. 011 evaporation of the solution at 70 C., 2.15 parts of a light greenish resin were obtained. At 180 C. the condensation product produced a thick melt, curing to a dry powder.

Eacmplc 19 v Mole Malonic diamide..- 1 Formaldehyde 3 Sodium glycinate (from reaction of NaOH and glycine) 0.5 Ethylene gly 2.5

To 0.375 part glycine there was added 0.2 part NaOH in 2 parts water, 0.155 parte'thylene glycol, 2.43 parts formalin and 1.02 parts malonic diamide. The mixture was refluxed for 1 hour,

leaving a clear, homogeneous, yellow solution.

Upon evaporation, a hard, pale green, resinous condensation product which caked at body tem- Nineteen parts glycine. 4 Parts Pyri n an 300 parts water were first mixed and to the solu-' tion there were added 1600 parts of exactly neutral formalin (pH '7) followed by the addition of -600 parts urea. The mixture was shaken until solution occurred. The pH dropped to 6.2. The

' solutionwas then refluxed for about 2.5 hours, resulting in a clear, water-white solution of increased viscosity. Eighty parts water were then removed by vacuum distillation, leaving an aqueous resinous solution with a resin' content of about 45% and a pH of 5.2. Alpha cellulose sheets were impregnated by dipping into the dehydrated resin solution. The sheets were dried at 50 C. for about 20 minutes and were laminated by molding at 130 -C., and under a pressure or about 2000 pounds per square inch to give a clear, homogeneous product, the translucency 01' which depended on the number of superposed sheets comprising the laminations.

The dry impregnated sheets may be first comminuted and ground to any desired mesh to be used in the preparation of other molded products.- It is not essential, however, that the tiller be impregnated in sheet form, since flock, wood flour, asbestos and the like may be first impregnated and then dried to a satisfactory condition for molding. Pigments and dyes may. be added either to the resin syrup or filler to give colored products. Opaciflers such aslithopone, or titanium v phthalate, may be used to decrease the transparency oi the molded or laminated products,

aseasie fii thereby lncrelng their opacity.

it is advisable to incorporate a id lubricant with the M0111: oommsit.

It the resin solution is dehydrated to a so I l irom bubbles aridblisters;

Ezamle 21 Mole (approximately) Urea 1.0 Formaldehyde 2.0

Glycine 0.035

Sodium gl'ycinate (from reaction of NaOH and glycine) 0.035

Two and six-tenths (2.6) parts glycine were added to 0.7 part NaOH in 20 parts water, and this solution was added to 80 parts or exactly neutral formahn (pH 7). Thirty parts urea were added and the mixture shaken until solution occurred. The mixture was allowed to stand at 35 C. plus or minus 5 C. for 10 hours. Alter solution occurred the pH was, 6.1, which dropped to 4.3 at the completion of the reaction.

The syrup was compounded with alpha flock to give a resin content of 60%, followed by drying at 50 C. for 90 minutes. A hard, translucent pound at 135 C. under a pressure of 2000 pounds per square inch. The addition or 5% dimethyl phthaiate to the compound gave a molding composition of increased plasticity or flow.

Example 22 Mols (approximately) Urea 1.0 40 Formaldehyde 3.0

Glycine 0.046 Sodium glycinate (from reaction 0! glycinc and NaOH) 0.046

Three and fifty-five hundredths (3.55) parts glycine and 0.95 part NaOH were dissolved in 20 parts water and the solution added to 120 parts exactly neutral (pH '7) formalin. Thirty parts urea 'were then added with agitation until solution occurred. The pH value of the solution at this point was 6.2. The reaction was allowed to continue at 35 C. plus or minus 5 C. for about ducing a very translucent product with a high glossy surface.

Example 23 Y Mols (approximately), Urea 0.67 Thio'urea 0.33

Formaldehyde 2.0 Glycine 0.014 Sodium glycinate (from reaction of NaOH and glycine) 0.095 7 Isopropyl alcohol 0.41

The gIycine sodium giycinate mixture. was first prepared by adding 1.9 parts NaOH to 4.1 parts glycine in 30 parts water, and to it was added parts neutral formalin, 20 parts urea, 13 parts disc was produced by molding the dried comthioureaand 14 parts isopropyl alcohol. The solution was refluxed for V hour and dehydrated to a resin content of about 50% and a final pH of 4.9. impregnated sheets were laminated, giving laminations which were hard, glossy, waterwhite and exceptionally translucent.

Example 24 Mols (approximately) Urea 1.0 Formaldehyde 2.0 Glycine 0.025 Pyridine glycinate (from reaction of pyridine and glycine) 0.03

One and twenty-three hundredths (1.23) parts pyridine were added to 2.07 parts glycine in 25 parts water and the technique as given in Example 20 was followed, using 80 parts neutral formalin and 30 parts urea. After solution of the urea the pH was 5.8 and at the completion of the reaction had dropped to 4.3. Laminations coated and impregnated with the heat-hardened material were translucent and had a glossy surface.

Example 25 Mols (approximately) Urea 0.67 Thiourea 0.33 Formaldehyde 2.0 Pyridine 0.043 Pyridine glycinate (from reaction of pyridine and glycine) 0.056 Isopropyl alcohol 0.28 Ethylene glycol 0.10

A resinous composition was prepared in accordance with the procedure given under Example 23, using 20 parts urea, 13 parts thiourea, 80 parts neutral form alin, 2.1 parts glycine, 3.9 parts pyridine, 14 parts isopropyl alcohol and 3 parts ethylene glycol. A clear, resinous syrup possessing a very good cure was obtained. The final pH of the syrup was 5.7. Excellent molded articles were produced by dispersing a filler in this resinous material and molding under heat and pressure.

li'arample 26 Mols (approximately) Urea 1.0 Formaldehyde 2.0 Glycine 0.0033 Sodium glycinate (from reaction of NaOHand glycine) 0.05

Example 27 Mols Pyridine 2 Formaldehyde 1 Glycine 1 Biguanide sulfate 1 To 1.59 parts pyridine and 0.75 part glycine in 4 parts water were added 0.81 part formalin and 1.99 parts biguanide sulfate. The resulting mixture was allowed to stand for about 18 hours at room temperature. resulting in a homogeneous yellow solution, which upon evaporation to dryness yielded an orange-colored, sticky powder.

Example 28 Mols Acetamide 1 Formaldehyde 1 Glycine 1 One part of acetamide, 1.37 parts formalin and 1.27 parts glycine were mixed, resulting in a clear solution which was allowed to stand at room temperature for 48 hours. The solution was evaporated at 70 C., resulting in a light cream-colored material which showed signs of melting with decomposition at about C. and which melted completely at C. The product comprised impure N-(methylene glycine) acetamide.

CHsCONHCHaNI-ICHzCOOI-I from which the pure material could be obtained by recrystallization from alcohol or from alcoholwater mixtures. Conversion to the salt derivative is readily accomplished by adding an alcoholic or aqueous solution of an inorganic base. Liquid organic bases may be added directly if so desired. The acetamide in the above example may be replaced by other monoamides, as for example, propionamide, butyramide, caproic acid amide, heptamide, caprylic acid amide, capric acid amide, toluene sulfonamide, benzamide, cyanoacetamide, acetoacetamide, etc. When amides insoluble in the aldehyde are used, the

reaction may be facilitated bythe use of heat under reflux or by using a mutual solvent aided by heat. Other aldehydes such as acetaldehyde and benzaldehyde, or aldehydes belonging to the unsaturated series, for example acrolein and methacrolein, may be used.

Sodium glycinate was prepared by adding 0.68 part NaOH to 1.27 parts glycine in 2 parts water. To the glycinate soution were added 1 part acetamide and 1.37 parts formalin. Heat was liberated from the mixture, and there was obtained a clear, homogeneous solution. Evaporation of this solution at 70 C. resulted in 2.66 parts of a white pasty mass, which was converted to powdered form upon prolonged drying. The product comprised the sodium salt of N- (methylene glycine) acetamide.

Preferred resinous compositions of this invention comprise the reaction product of one mol of a polyamide, for example urea, at least one moi of an aldehyde; as for instance formaldehyde, and not exceeding substantially 0.3 mol of a mixture of an aldehydewreactable amino acid (e. g., glycine) and a derivative, for instance a salt, of an aldehyde-reactable amino acid, for example sodium glycinate, the mol ratios of the amino acid and the derivative of the amino acid with respect to each other being adjusted to give a predetermined pH. It will be understood, of course. that the salts and other derivatives of aldehydethe adehyde, depends upon the NH: group of the amino acid.

Products of this invention are especially suitable for use as fire-retardants, water-repellents and sizings, when applied to wood or the like, or to silk, cotton, wool, synthetic organic fibers, etc., in continuous filament, thread, fabric (woven or felted) or other form. The cellulosic or other fibrous materials to be treated may be surface coated or both coated and impregnated by any suitable means, for example, by spraying with, or immersing in, a solution of the treating agent and thereafter volatilizing the solvent. The resinous condensation products of this invention, alone or in conjunction with other natural or synthetic resinous materials, as for example phenolic resins, alkyd resins, vinyl compounds such as polyvinyl alcohol, polyvinyl acetals, etc., have a wide variety of uses, for instance in the production of laminated and molded products, as casting resins, in paints, varnishes and other protective surfacing materials, in the manufacture of arc-extinguishing tubes capable of evolving an arc-extinguishing gas under the heat of the arc, in the production of wire or baking enamels, and for other uses.

In my divisional application Serial No. 497,682, filed August 6, 1943, and assigned to the same assignee as the present invention, I have claimed products obtained by eifecting reaction between ingredients including a salt of suifamic acid,

formaldehyde and a polyamide selected from the class consisting of urea, thiourea, malonic diamide, succinic diamide, citric triamide and phthalamide, and methods of making the same.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A composition of matter comprising the resinous product of reaction. in the absence of a protein, of ingredients including (1) a polyamide selected from the class consisting of urea, thiourea, phenyl thiourea, malonic diamide, succinic diamide, citric triamide and phthalamide, (2) an aldehyde and (3) a salt of a cry'stalloidal amino carboxylic acid.

3. A composition of matter comprising the resinous product of reaction, in the absence of aprotein, of ingredients including (1) urea, (2) formaldehyde and (3) a salt of a crystalloidal amino carboxylic acid.

3. A composition of matter comprising the of a protein. of ingredients including urea, formaldehyde and sodium glycinate.

4. A composition of matter comprising the resinous product of condensation, in the absence resinous product of reaction, in the absence of a g protein, of ingredients including (1) a polyamide selected from the class consisting of urea, thiourea, phenyl thiourea, malonic diamide, succinic diamide, citric triamide and phthalamide,

, (2) an aldehyde. (3) a crystalloidal amino carboxylic acid and (4) a salt of a crystalloidal amino carboxylic acid.

5. A composition of matter comprising the resinous product of reaction, in the absence of a protein, of ingredients including (1) urea, (2)

formaldehyde. (8) a crystalloldal amino carboxylic acid and (4) a salt of a crystalloidal amino carboxylic acid.

6. A composition of matter comprising the resinous product of condensation, in the absence of a protein. of ingredients including urea. formresinous product of condensation, in the absence of a protein, of ingredients including urea, formaldehyde, glycine and sodium glycinate.

8. A resinous composition comprising the product of reaction, in the absence of a protein, of ingredients comprising the following components inthe stated molar ratios: (1) one mol of a polyamide selected from the class consisting of urea, thiourea, phenyl thiourea, malonic diamide, succinic diamide, citric triamide and phthalamide, (2) at least one mol of an aldehyde, and (3) not exceeding substantially 0.3 mol of a mixture of a crystalloidal amino, carboxylic acid and a salt of a crystalloidal amino carboxylic acid, the mol ratios of the said amino acid and of the said salt with respect to each other being adjusted to give a predetermined pH.

9. A heat-curable resinous composition comprising the heat-convertible product of condensation, in the absence of a protein, of ingredients including the following components in the stated molar ratios: one mol urea, at least one mol formaldehyde, and not exceeding substantially 0.3 mol of a mixture of glycine and sodium glycinate, the mol ratios of glycine and sodium glycinate with respect to each other being ad- Justed to give a predetermined pH.

10. A product comprising the cured resinous composition of claim 9.

11. The process of preparing a resinous composition which comprises effecting reaction, in the absence of a protein, between ingredients comprising the following components in the stated molar ratios: (1) one mol of a olyamide selected from the class consisting of urea, thiourea, phenyl thiourea, malonic diamide, succinic diamide, citric triamide andphthalamide, (2) at least one niol of an aldehyde, and (3) not exceeding substantially 0.3 mol of a mixture of a crystalloidal amino carboxylic acid and a salt of a crystalloidal amino carboxylic acid, the moi ratios of the said amino acid and of the said salt with respect to each other being adjusted to give a predetermined pH.

12. A resinous composition obtained by reaction, in the absence of a protein, of ingredients comprising urea, formaldehyde and glycine, said reaction being effected while the said components are admixed with an alkaline substance.

13. The process which comprises reacting to sence of a protein, between ingredients including the product of (1) and a polyamide selected from the class consisting of urea, thiourea, phenyl thiourea, malonic diamide,- succinic diamide, citric triamide and phthalamide.

15. The process which comprises reacting a salt of glycine with formaldehyde and urea in the absence of a protein.

16. The process which comprises eflecting reaction, in the absence of a protein, between ingredients including an N-methylol glycine salt and urea.

GAE'I'ANO F. D'ALELIO. 

